Evidence for placing the Neu-1 locus within the mouse H-2 complex.

Congenic lines B10.KPA42, B10.KPA132, B10.SNA57, B10.DRB62, and B10.WOA105 carry H-2 haplotypes of wild mice on the genetic background of the strain C57BL/10Sn. Two of the lines (B10.DRB62 and B10.WOA105) have H-2 haplotypes indistinguishable from H-2v of B10.SM. The H-2 haplotype of one line (B10.SNA57) seems to have arisen from H-2v by recombination between the D and Qa-2 loci. The H-2 haplotypes of the remaining two lines probably arose from H-2v by recombination between the C4 and D loci. Since all six and no other lines carry the rare Neu-1a allele, the neuraminidase-1 locus is probably located proximal to the H-2D locus. Typing of H-2s recombinants for the enzyme acid phosphatase liver, the processing of which is controlled by the Neu-1 locus, suggests that the locus resides between the E alpha and D loci, that is in the S region.